Thirty-four pages of research, branded with a staid title and rife with complicated graphs, might not seem like a scintillating read, but there’s no doubt that a report released on Wednesday will punch higher education's hot buttons in a big way.

The report, "Labor Intensive or Labor Expensive: Changing Staffing and Compensation Patterns in Higher Education," says that new administrative positions—particularly in student services—drove a 28-percent expansion of the higher-ed work force from 2000 to 2012. The report was released by the Delta Cost Project, a nonprofit, nonpartisan social-science organization whose researchers analyze college finances.

What’s more, the report says, the number of full-time faculty and staff members per professional or managerial administrator has declined 40 percent, to around 2.5 to 1.

Full-time faculty members also lost ground to part-time instructors (who now compose half of the instructional staff at most types of colleges), particularly at public master’s and bachelor’s institutions.

And the kicker: You can’t blame faculty salaries for the rise in tuition. Faculty salaries were "essentially flat" from 2000 to 2012, the report says. And "we didn't see the savings that we would have expected from the shift to part-time faculty," said Donna M. Desrochers, an author of the report.

The rise in tuition was probably driven more by the cost of benefits, the addition of nonfaculty positions, and, of course, declines in state support.

Howard J. Bunsis, a professor of accounting at Eastern Michigan University and chair of the American Association of University Professors’ Collective Bargaining Congress, wasn’t surprised by the conclusions of the study.

"You see it on every campus—an increase in administration and a decrease in full-time faculty, and an increase in the use of part-time faculty," he said. With that trend, along with rising tuition and falling state support, "you're painting a pretty fair picture of higher ed," he continued. "It's not what it should be. What's broken in higher ed is the priorities, and it's been broken for a long time."

Growth in Student Services

Administrative bloat has been a perennial hot topic in academe—in some ways, as hot as college costs. And the two are frequently linked in debates over the future of higher ed. Some observers—both inside and outside the industry—have cited an ever-expanding bureaucracy as one cost driver, while other observers have said that staff growth merely reflects the new things colleges do and the new roles they are expected to perform.

The Delta Cost Project's report is unlikely to put the debate to rest, but it might provide a clearer picture of what’s happening in various sectors of the industry. In terms of adding manpower, private research institutions maintained a clear lead over other kinds of colleges. Their average headcount of employees per 1,000 students—at 456 in 2012, up from 434 in 2000—was far higher than public research universities or private master’s and bachelor’s institutions.

Generally, from 2000 to 2012, colleges expanded their use of part-time instructors per student, while the numbers of full-time instructors stayed flat or fell behind.

Among the sectors, however, there were anomalies: Private research universities again stood out, as the only kind of institution that added full-time professorships—an average of 16 per 1,000 full-time-equivalent students.

Community colleges stood out in another way: They lost positions not only among full-time faculty members per student, but also among part-time faculty members—the only sector to do so. (While community colleges were falling behind on instructors, they were adding professional staff members—an average of three positions per 1,000 students.)

Across the board, the ratio of full-time-equivalent faculty members to administrators has declined sharply since 1990. Notable declines have occurred at public master’s and private bachelor’s institutions. (See chart below.)

The report also makes clear that the expansion in wages and salaries derived not from instruction, institutional support, or academic support, but from student services, which can include athletics, admissions, psychological counseling, and career counseling, among other activities. Nearly every type of college had increases in that area, with little growth, or even declines, in other areas.

A Question of Mission

So why is that happening, and is it for the good of institutions or not? That’s up for debate, depending on your perspective. Robert E. Martin, a professor emeritus of economics at Centre College who has studied the effect of administrative bloat on college costs, said that the role of student services has been growing since the early 1990s, when colleges believed that they had to provide more services outside the classroom.

Those services aren’t necessarily central to the mission of most institutions, Mr. Martin said. "At what point," he said, "does that ratio of nonacademic staff to tenured faculty become completely untenable?"

Other industries have found ways to outsource services that are not central to what they do, but higher education has invested more and more—as part of a strategy, he contended. Just as a cable company bundles channels together and makes you pay for them all, whether or not you watch them, colleges have bundled counseling, athletics, campus activities, and other services with the instructional side to justify charging more.

"All of those things they are bundling are adding to the price of attendance," he said.

Naturally, people in student services see it differently. Patricia L. Leonard, vice chancellor for student affairs at the University of North Carolina at Wilmington, said that growth in student services might reflect colleges’ response to increased regulation and pressure from parents and policy makers.

Faculty members typically don't deal with legal disputes, government regulations, athletics compliance, or intervention in mental-health, sexual-assault, or disabilities issues—that’s the professional staff's job, she said.

"When you put that all together, there may be increased staff, but it's because campuses are trying to meet the need," she said. "Any one case is extremely time-consuming."

People have come to expect that education extends to activities outside the classroom, she said. Many of her staff members not only coordinate with instructors, but also teach classes.

"It’s an integrated approach," she said, "and I don’t think that would happen if it were outsourced."